Automatic cut-off device for oil-burner motors



Oct. 26 1926. 1,604,493

I. E. SMITH AUTOMATIC CUT-OFF DEVICE FOR OILI BURNER MOTORS Original Filed NOW 17. 1924 2 Sheets-Shet 1 INVENTOR Ira 1 7. Sm 5611 BY @.u.ml,

ATTORNEY Oct. 26 1926.

I. E SMITH AUTOMATIC CUT- OFF DEVICE FOR OIL| BURNER MOTORS 17, 1924 2 Sheets-Sheet 2 Origin l Filed NOV.

Fly. .5

[I I ll-Ill [I' Ira E. Sm 12th BY m m ATTO R N EY Patent ed Get 1926.

UNITED S 'TATES PATENT-OFFICE,

m n. siarrn, or srocx'ron, cunt-61mm.

aoroua'rrc coir-oar nnvron r03. orn-numn morons.

Original application fled November 17 1924, Serial No. 750,248.- Divided and this application filed. June I so, 1926. Serial No. 118,826.

This invention relates to improvements in electrically driven oil burning apparatus, and particularly represents a div sional application of m co-pendlng application for Ii patent oh oil urning apparatus,.filed Novembe-r'17th, 1924, Serial No. 750,248.

The present application relates to the automatic cut-off device for the oil burner motor, my principal object bein to provide a simple and positively acting evlce to cause the motor to be stopped in the event that an excessive su ply of oil, which is not all being burnt, is Being fed to; the burner plate, or the float contro ed supply dev1ce itself floods and overflows.

This stoppingof the motor,without the presence of an operator being necessary,

prevents possible damage from. fire which might occur around the burner if the defective flow of oil were allowed to continue unnoticed, and also notifies the operator when such conditions obtain so that he may make the necessary investigation. and adjustments before again, attempting to start the motor.v

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a erusal of the following specification and c aims. I

80 A In the drawings similar'characters of reference indicate, corresponding parts in the several views:

Fig. 1 is a side elevation of the. complete unitary assembly of-the apparatus.-

Fig. 2 is a detached and enlarged view of an automatic motor circuit controllingmember whose action is controlled by an overflow of oil either from the burner or from the float control supply member. Fig. 3 is a sectional view of the burner detached. p

Referringnow more particularly tothe characters of'reference on the drawings, the burner in general comprises a vertical and 4.5 tubular casing in which is turnabl'y and closel fitted a shaft 2.. On the lower end of this shaft is a centrifugal pump runner 3 adapted to take oil from a passage .4 formed-in a bottom ca leading to the top of the shaft.

plate 7 of suitable character onto whidh the oil from the passe e .6 is ,thrown with the rotation of the sh 2; and the opefation of 5 and to discharge such oilthrough suita le passage means 6 v i open topped tank 23 positioned adds. On top of the shaft is mounted a burner.

one end of'a lever is fulcrumed on a bracket 26 which the pump. Mounted on the shaft 2 below the plate is a gear 8 driven-from a shaft 9 connected to an electric motor 10. The motor and easing 1 are rigidly mounted in unitary relation-on a common base 11. 1 p

The burner plate is surrounded by a casing 12 having an opening 13 at the bottom thereof'under which. opening and fixed on the member 1 is a dish 14. This dish has a downward slope towards its center and is adapted to catch any excess oil dropping from the burner plate and casin 12 and for some reason not consumed wit the operation of the burner. vA drain pipe 15 leads from this dish to a device hereinafter explained. a i

Also mounted on the base 11 adjacent the outer end thereof is an oil supply control device, comprising a bowl 16 having afloat 17 thereon which automatically controls the seating'of a needle valve 18 in the oil intake passage 19, so that the oil in the body may. be maintained at a definite level as at A, and at the same time the-oil pump 3 will be supplied with the necessary amount of fuel. This form of construction being common to various carbureters and the like, as will be evident, no= further ex lanation. of the working thereof is thoug t necessary. The oil is preferably fed to the intake 19 in a suitable manner, preferably by means of apump 20 driven by the motor 10.

An outlet pipe 21 leadsfrom the bowl 16 near the bottom thereof to the passage 4 of the casing 1, so as to supply the pump 3 with a gravity flow' of oil. I

A pipe 22 leads downwardl from the bowl 16 above the normal oil evel line A thereof, so as to take oil away from thebowl in the event that the float or valve stick or fail to function properly and causing the oil to riseto an undue height in the bowl.

Automatic shut-downx of the motor, should the above conditions in the bowl obtain, or if oil should be excessively 'discharged into the dish 36 of the burner, is provided for by the following structure:'

Both pipes 15 and 22 empty into a small cent the base at any suitable point outsi e the furnace and havin abail 24'removably hung orizontal lever 25. This is mounted on the base 11. A weight 27 on the levercounteracts the weight of the tank 23 when the latter is empty, this counteracting weight, after a small amount of oil has flowed into the tank, being 'aided by the weight of a float 28 in the tank and held clear of the bottom thereof, as-will be here inafter seen. The bracket 26 is of such a height that the tank is freely suspended clear of the base.

Vertically opposed contacts 29 are ar ranged in connection with the weight 27, these contacts being normally spaced from but adapted to alternately engage contacts 30 fixed on the bracket 26; In the main circuit leads 31 to the motor 10 is interposed a normally closed switch 32 preferably of the thermostat type. The heating element 33 of this switch is connected by a lead 34 to the corresponding lead 31 ahead of the switch, and has a connection with the contacts 29 through the bracket 26 and lever 25. The contacts 30 are connected in common to the other lead to the motor by means of a lead35.

The stem 36 of the float 28 has a yoke 37 straddling the lever 25 on the opposite side of the fulcrum thereof from the bail 24. This yoke has a cross pin 38 below the lever adapted to engage the same only after the float has risen a certain distance. A similar pin 39 is mounted in the yoke above the lever and is normally just clear of the same.

The float is normally supported clear of the tank and the pin 39 clear of the lever by means of adjustable nuts 40 on the float stem, which nuts rest on an extension 26 of the bracket, said extension also forming a guide for the stem. The nuts are preferably adjusted so that the pin 39 is just barely clear of the lever when the tank is empty.

Therefore, while the weight 27 alone counterbalances the weight of the empty tank, as soon as any oil flows into the latter and the lever adjacent the pin 39 starts to rise, said pin will takehold and the weight of the float will then aid in counteracting the weight of the tank. In this manner, a relatively large amount of oil may flow into the tank before, the upper contacts 29 and 30 engage each other, as will be evident. After a certain amount of oil has entered the tank, however, either through the ipe 15 or through the pipe 22,the .counter alancing effect of the weight 27 and that of the float will be overcome. This will cause the tank to lower and the thermostat switch ,heater circuit to be closed at the upper contacts 29-and 30. The heater elenient 33 of said switch will therefore be heated, caus is disconnected from the lever 25 for emptying, the removal of its weight from the lever causes the weight 27 to be lowered so that" the lower contacts 29and 30 become engaged. This of course causes the stoppage of the motor in the same manner as above, so that the latter cannot be run or the burn er operated until the tank is replaced in position on the lever in an empty condition.

Should any person attempt to frustrate the. functioning of the device by blocking up the tank 23 so that it will not lower when oil drains therein, the rising float with the accumulation of oil in the tank will cause the lever to tilt and the upper contacts 29 and 30 to be engaged just the same as if the tank itself were lowered and caused this movement of the lever to take place. This is because after the float has risen a certain distance the pin 38 bears against the lever 25 causing the latter to move without any movement of the tank itself. When the lever thus moves, while the. tank is stationary, the end of saidvlever adjacent the tank drops away from the bail 24, but since this bail is not permanently afiixed to the lever no. strain is placed on the lever or bail.

I am aware that overflow tanks, operating knife-switches, have been used for a similar purpose. As far as I am aware however, they only operate in one direction, that is when the tank is lowered with a weight "of oil therein. As soon as these tanks are removed, the circuit is restored to an unbroken condition.

This is contrary to my arrangement, with which breaking of the motor circuit is had when the tank is full, when it is removed, and if the tank should be blocked up and prevented from downward movement. This construction meets the requirements of the Fire Underwriters, in providing a devicev which automatically operates .under any and all conditions. Further, the'partieular form of motor circuit control switch enables the switch control circuit to be of low voltage, which allows abutting and sensitive contacts to be used instead of the knife switch which requires more power.

- From the foregoing description it will be of the invention as set forth herein.

While this specification sets forth in detail the present and preferred'construction of the device, still in practice, such devia tions from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined bythe appended claims.

Having thus described my invention what I claim as new and useful and desire to secure by'Letters Patent is:

1. In an oil burner having a burner member onto which oil is fed, an electric motor by means of which oil is fed to the member, means for catching any excess oil from the member, a normallycounterbalanced and suspended tank into which-such excess oil 1s automatically discharged, said tank being removable, and'means whereby when the tank is either removed, or overbalanced by the weight of acertain amount of oil therein, .the motor will be automatically stopped.

I 2. In an oil burner having a burner member onto which oi1-is fed, an electric motor by means of which oil is fed to the member,

means for catching any excess oil from .the

, member, a tank into which said oil is auto matically discharged, a horizontal lever on which the tank is removably hung, means on the lever normally holding the tank counterbalanced, a normally closed switch in the motor circuit, an independent and normally open circuit for opening the switch, and

.means whereby movement of the lever :in

either direction about its ,fulcrum will cause the switch-opening circuit to be closed.

3. In an oil burner having a burner member into which oil is fed, an electric" motor by means of which oil is fed-to the member, a normally closed switch in the motor circuit, a lever, a normally counterbalanced tank suspended from'the lever into which an excess oil from the plate is automatlcally fe means whereby a movement of the lever caused by the downward movement of *the tank when oil enters the same, will cause the switch to be opened, fl'oat means in the tank, and means between the lever and float whereby if the tank is prevented from downward movement the 'float will cause mavement of the lever to open the switch when oil flows into the tank;

-- 4. In an oil burner having a burner member onto which oil is fed, an electric motor by means of which oil is fed to the member,

a normally closed switch in the motor circuit, a lever pivoted intermediate its ends, a tank suspended from one end of the lever, a

weight on the other end of the lever nor mally counterbalancing the weight of "the empty tank, a float in the tank, means whereby reason of a certain amount of oil in'the tank, the switch will be 0 ened.

In testimony whereof affix my signature. 1

IRAE. sMrrH. 

